HYDROGEN CYANIDE (HCN) IS ONE OF THE MOST COMMON MOLECULES EXISTING IN MANY PLANETARY ATMOSPHERES SUCH AS JUPITER NEPTUNE AND TITAN AS WELL AS IN BOTH GALACTIC AND EXTRAGALACTIC SOURCES INCLUDING COMETARY ATMOSPHERES T TAURI STARS EXTRAGALACTIC RED GIANTS AND AGB STARS ETC. IN MANY INTERSTELLAR CLOUDS THE HIGH-LYING ISOMER HYDROGEN ISOCYANIDE (HNC) IS OFTEN FOUND TO BE AS ABUNDANT AS HCN. MODELS HAVE SHOWN THAT INCLUDING HCN MAY ALTER THE OPACITY OF A PLANETARY ATMOSPHERE BY ONE OR TWO ORDERS OF MAGNITUDE. ALSO HNC MAY PLAY AN IMPORTANT ROLE IN THE OPACITY OF HCN CONTAINING OBJECTS. CONSIDERING THAT HCN HAS BEEN FOUND IN HOT-JUPITER EXOPLANETS AND THE FIRST SUPER-EARTH EXOPLANET ATMOSPHERE DETECTION OF 55 CANCRI E ALSO HINTS AT THE PRESENCE OF HCN A HIGHLY ACCURATE AND COMPLETE HCN/HNC LINE LIST THAT PERFORMS UP TO 2000-3000K IS NEEDED. THE LINE LIST WILL HELP ASTRONOMERS TO ANALYZE AND SIMULATE THE EXOPLANET SPECTROSCOPIC DATA MORE ACCURATELY AND RELIABLY DETERMINE THEIR ATMOSPHERE CONDITIONS WHICH WILL ENABLE FUTURE PLANETARY SCIENCE STUDIES. THE CURRENT HITRAN DATABASE HAS ONLY ~3000 TRANSITIONS UP TO 3400 CM-1 FOR HCN AND ~600 TRANSITIONS FOR ITS 13C OR 15N ISOTOPOLOGUES. THE EXOMOL HCN/HNC LINE LIST (BARBER R.J. MNRAS 2014 437 1828) WAS UPGRADED FROM AN AB INITIO COMPUTATIONAL LINE LIST WHERE ~168 000 LEVELS WERE REPLACED BY EXPERIMENTALLY DETERMINED VALUES AND PREDICTIONS. WITH BAND ORIGINS CORRECTED THE ORIGINAL LEVELS WERE STILL OFF BY ~1 CM-1 OTHERWISE IT COULD BE DOZENS OF CM-1 FOR THE HIGH-LYING STATES. THE MODEL BASED PREDICTIONS PROBABLY DIVERGE AT HIGH J'S. THE 3~4% UNCERTAINTY OF THE ENERGY DIFFERENCE BETWEEN THE HCN / HNC MINIMA MAY LEAD TO ~10% OPACITY VARIATION AT HIGH TEMPERATURE. THE AB INITIO INTENSITY WILL BE LESS RELIABLE FOR THE HIGHER ENERGY REGION WEAK BANDS AND HOT BANDS. ALL THESE WILL AFFECT THE ACCURACY OF DATA ANALYSIS. IN ADDITION THE LINE LISTS OF D 13C 15N RELATED ISOTOPOLOGUES ARE MUCH FURTHER FROM COMPLETENESS. IN SHORT THE LATEST EXOMOL LINE LIST IS NOT REALLY SUITABLE FOR HIGH ENERGY AND ESPECIALLY HIGH TEMPERATURE STUDIES OF PLANETARY AND EXOPLANETARY ATMOSPHERES. WE PROPOSE TO COMPUTE A SELF-CONSISTENT HIGHLY ACCURATE&COMPLETE IR LINE LIST FOR THE HCN/HNC SYSTEM AND ITS ISOTOPOLGOUES. THE BEST THEORY + HIGH-RESOLUTION EXPT DATA STRATEGY WAS ADOPTED OVER THE LAST DECADE FOR THE BEST AVAILABLE IR LINE LISTS OF CO2 AND SO2 WHERE EXACT QUANTUM ROVIBRATIONAL HAMILTONIAN CALCULATIONS WERE CARRIED OUT TO REFINE AN AB INITIO PES WITH SELECTED EXPERIMENTAL DATA. THE SUPERIORITY OF THIS STRATEGY IS FOR PREDICTIONS! IN ADDITION TO REPRODUCING MOST EXISTING MEASURED TRANSITIONS WITH 0.01 - 0.02 CM-1 AND 2-10% INTENSITY DEVIATIONS WE CAN MAKE PREDICTIONS WITH SIMILAR ACCURACY. PREDICTIONS HAVE BEEN CONFIRMED BY MANY RECENT EXPERIMENTS: OUR SO2 LINE LISTS MATCH LINE-BY-LINE TO THE IR PEAKS OBSERVED IN THE LAB; OUR CO2 LISTS BASED IR SIMULATIONS ARE BETTER THAN HITEMP WHEN COMPARED WITH 1550K AND 1773K SPECTRA. COMPARED TO DATABASES HITRAN GEISA AND CDSD ETC. OUR LISTS ARE FAR MORE COMPLETE MORE SELF-CONSISTENT AND MORE RELIABLE WHEN EXTRAPOLATED TO HIGHER TEMPERATURES AND A HIGHER ENERGY RANGE. WE CAN ALSO GENERATE ISOTOPOLOGUE LINE LISTS WITH SIMILAR ACCURACY E.G. THE AMES IR LISTS FOR 13 CO2 ISOTOPOLOGUES ARE ACCURATE UP TO 18 000 CM-1 AND 1500K WHICH ARE THE MOST COMPLETE AND RELIABLE CO2 IR LISTS FOR HOT-JUPITER LIKE EXOPLANETS. BY ADOPTING THIS PROVEN STRATEGY AND USING THE LATEST EXPERIMENTAL INFORMATION WE EXPECT THE NEW HCN/HNC LISTS TO HAVE SIMILAR QUALITY AND RANGE AS WE HAVE ACHIEVED FOR CO2 AND SO2 I.E. WORKING UP TO 2000K OR HIGHER. THE NEW LINE LISTS WILL BE DEPOSITED ONTO THE NASA PDS OR HITRAN DATABASE.THIS STUDY RESPONDS TO THE CALL OF PLANETARY DATA ARCHIVING RESTORATION AND TOOLS SEC.1.5 "GENERATION OF NEW REFERENCE INFORMATION AS THE PROPOSED HCN/HNC LINE LISTS IS INTENDED FOR GENERAL USE IN PLANETARY (ATMOSPHERE) SCIENCE.